Posted: Sat Nov 15, 2008 12:16 pm Post subject:
Rev 28 Design
Hey Scott,
I have most of the rev 28 schematic perfboarded and functioning. I know the schematics have changed drastically since rev 28 and you have added a whole host of cool new things, but I wanted to get my feet wet with the Softpots. I have a couple of questions if you don't mind about rev 28.
1.) Did I read correctly that you have the ref voltages on U14 set to +70mV on pin 6, and -70mV on pin3?
2.) Is the diff amp U13 (pins 1,2,3) set for unity gain?
I've been drooling prefusely all the way through this thread, I must say.
My question is; do people on this forum build in Euro-rack format at all? I see a lot of boards that are very oblong, and would be difficult to place in these, traditionally shallow and not very tall, cases.
I don't think it'll be a problem for me, because I'd do a "Twinpendage", where the need for panel space would outgrow the 20x10 cm rather quickly anyway
But the idea of splitting it into multiple boards that could be stacked with spacers does appeal to me as well, since that would let us build euro-format front panels for these without having to tuck the pcb away somewhere in the case.
Now, any ETA on this? Does funding need to come in from elsewhere to make the printing happen?
AND.... drum-roll.... will there be kits?
Joined: Apr 17, 2006 Posts: 2810 Location: New York
Audio files: 24
Posted: Tue Nov 18, 2008 8:27 am Post subject:
Quote:
But the idea of splitting it into multiple boards that could be stacked with spacers does appeal to me as well, since that would let us build euro-format front panels for these without having to tuck the pcb away somewhere in the case.
I thought about that for a bit but then realized that if you take into consideration the amount of inputs, outputs and controls, the panel size would be fairly large to accommodate them. Thus, it was decided to make one large board for this reason and mount the board to the panel. Also, the cost involved in low volume, two board sets, is much more expensive. I find that when you mount PCB's to panels, it's best to use the "Tyco/Amp MTA" style connector housings so that the wires can be dressed downward towards the panel. Looks much neater. I will most likely specify that style connector for the build.
I have included several power connectors on the board, however, that will allow you to connect to FRAC, MOTM, DOT-COM, Doepfer A100, and two user connectors including a terminal block for the ultimate in power connectivity.
Quote:
Now, any ETA on this? Does funding need to come in from elsewhere to make the printing happen?
AND.... drum-roll.... will there be kits?
Scott and I have discussed this and I (sMs Audio Electronics) will be distributing Parts Kits and PCB's. Scott will have a full set of comprehensive documentation as usual. Hmm, ETA, I will let Scott handle that question. Lets just say that I am just about ready to order the bare prototype PC boards so that two to three units can be built and tested. Scott has really nailed the circuit down so no more changes are expected. The prototype build is an effort test the integrity of the PCB design and the circuits behavior in it's new environment. Once this is all done, we begin distribution.
Joined: Jun 19, 2007 Posts: 178 Location: Huntsville, AL (USA)
Posted: Tue Nov 18, 2008 10:21 am Post subject:
State Machine wrote:
I have included several power connectors on the board, however, that will allow you to connect to FRAC, MOTM, DOT-COM, Doepfer A100, and two user connectors including a terminal block for the ultimate in power connectivity.
So, I'll be able to hook up lemons to it? That would be sweet, er sour, er bitter-sweet! I could make lemon juice while squeezing out tunes on the ribbon - that is until my power supply is juiced out....... Eh.... Maybe I'll just stick to my 'MOTM' power supply so I can crank out tunes non-stop and simply squeeze juice with my free hand without worrying about the music coming to a halt.
Whatever, I'm just happy that this thing is really happening! I just hope it will be in time for me to be able to include it in my portfolio for my application to Georgia Tech's Masters of Science in Music Technology program _________________ Don't feed me Indian, you WILL regret it!
Joined: Dec 23, 2005 Posts: 4127 Location: Mount Hope, KS USA
Audio files: 96
Posted: Tue Nov 18, 2008 10:35 am Post subject:
Man, I'd hope it would be ready by then!
Yeah, Bill - "Yarp" entered my lexicon this summer when I was in Malaysia - the movie "Hot Fuzz" was playing on HBO there, repeatedly. The deadly trolley boy was one of my favorite characters in that flick....
Dang, I gotta make some more videos - I haven't touched on much of the Appendage yet (no pun intended). I made one last night with Hypertrigger, but, after actually watching it, found it annoying beyond belief, so I'm going to give it another crack. I think I need a cape for that one. _________________ My Site
Now, any ETA on this? Does funding need to come in from elsewhere to make the printing happen?
AND.... drum-roll.... will there be kits?
Scott and I have discussed this and I (sMs Audio Electronics) will be distributing Parts Kits and PCB's. Scott will have a full set of comprehensive documentation as usual. Hmm, ETA, I will let Scott handle that question. Lets just say that I am just about ready to order the bare prototype PC boards so that two to three units can be built and tested. Scott has really nailed the circuit down so no more changes are expected. The prototype build is an effort test the integrity of the PCB design and the circuits behavior in it's new environment. Once this is all done, we begin distribution.
Bill
wow! That's fantastic! I believe you have a real chance of making a lot of impact in the modular synth scene with this.
What was the latest control count? Knobs, switches, jacks? I may even start working on a layout for this!
Joined: Dec 23, 2005 Posts: 4127 Location: Mount Hope, KS USA
Audio files: 96
Posted: Wed Nov 19, 2008 6:58 pm Post subject:
Quote:
It's plain to see you are having WAY too much fun Scott
In HyperTrigger mode, it's kind of hard to stop - it's kind of like going down the side of a mountain and trying to brake yourself....
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go get yer 10 g's, scott
GATech certainly has it going on! Appendage seems pretty plain compared to some of those pics I saw....
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What was the latest control count? Knobs, switches, jacks? I may even start working on a layout for this!
That would be cool. I posted a doc covering that a few pages back. The only change is that the switch to select different ribbon lengths didn't pan out - everything else is in place.
I've started a doc about the Appendage, but it's not near to being done. It's called "Appendage Exposed: Getting In Touch With Your Appendage". I'm wondering how it will do with the Net Nanny programs....
What was the latest control count? Knobs, switches, jacks? I may even start working on a layout for this!
That would be cool. I posted a doc covering that a few pages back. The only change is that the switch to select different ribbon lengths didn't pan out - everything else is in place.
yeah, I asked because I got lost in the thread... very info-dense and long
Joined: Dec 23, 2005 Posts: 4127 Location: Mount Hope, KS USA
Audio files: 96
Posted: Thu Nov 20, 2008 7:59 pm Post subject:
If you want to balance out the right side, there are five outputs that don't appear on your panel - the inverted versions of the output voltages. I consider those optional, but one more output would square up the right side. The inverted output I've found most useful thus far is the inverted bend, and here's why:
If you're using the bend voltages to control VCA levels (for mixing in modulations), the inverted bend is very good for mixing something different in "going down" and something different in "going up". For example, you can patch the noninverted bend to the control input of a VCA that's controlling the amplitude of a VCO that feeds an FM signal to the external input. When you slide up, the VCA will introduce more and more FM into the signal. Then, patch the inverted Bend to a VCA that's controlling, say, a different modulation source (or even the same) to filter cutoff. Then, when you slide down, the filter is modulated more and more. Or, you could even instead patch the second VCO (the one that increases going down) straight to the external input, which in this case is acting as a mod input as well, albeit without a level control. Up would be one brand of FM, down would be another...and so on and so forth, etc., ad nauseum.
Joined: Dec 23, 2005 Posts: 4127 Location: Mount Hope, KS USA
Audio files: 96
Posted: Thu Nov 20, 2008 8:05 pm Post subject:
Or control two filters for a stereo patch - say slide or init could control the cutoff of the filters. Bend could additionally control one filter and inverted bend the other. Sliding up would brighten up one channel and lower the cutoff on the other, and the opposite would happen sliding down. The two filters, at the initial point of contact, would have the same cutoff, so as you slid up and down past the initial point of pressure, the signal would tonally pan right and left.
Oh, and by "external input", meant to say "mix input" in the previous post. _________________ My Site
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